My 33 Gal tall has a yeast-powered CO2 system. The design is simple: a heavy-duty plastic cylander with sugar-water and yeast, fed into the tank via a hose that ends in a commercial bubble counter.

I've noticed, however, that it's only useful for a few weeks at a time. I was just wondering if there's something I can add to the "reactor chamber" (as I like to nerdily call it) that will perhaps keep the yeast from over-populating and allow them to sustain a colony longer._________________http://auditorandagentleman.blogspot.com - now with 100% more fish.
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Not unless you wan't your c02 our-put to slow, even then I can't think of anything, and it doesn't die because it "over populate's" it dies because you are really just making alcohol which will kill the yeast._________________

My 33 Gal tall has a yeast-powered CO2 system. The design is simple: a heavy-duty plastic cylander with sugar-water and yeast, fed into the tank via a hose that ends in a commercial bubble counter.

I've noticed, however, that it's only useful for a few weeks at a time. I was just wondering if there's something I can add to the "reactor chamber" (as I like to nerdily call it) that will perhaps keep the yeast from over-populating and allow them to sustain a colony longer.

the only way was to use yeast like beer or wine.... usually can last than 20days

You need a larger "cylinder" so that the mixture has more water,
and you need to add a pH stabilizer of any type, because the alcohol will cause chaos with your pH which will kill your yeast before the alcohol has a chance to._________________NOTE: my avatar is a rare picture of a Youis gulliblei

You need a larger "cylinder" so that the mixture has more water,
and you need to add a pH stabilizer of any type, because the alcohol will cause chaos with your pH which will kill your yeast before the alcohol has a chance to.

I do not see how the ethanol produced by yeast will affect the pH._________________Anthony

I do not know all the science behind it, I just know the results.
Creating co2 makes a huge change in the water chemistry and huge changes in water chemistry cause pH fluctuation._________________NOTE: my avatar is a rare picture of a Youis gulliblei

alcohol is one of the metabolic byproducts of the yeast mixture, which means that pH change is caused by the creation of alcohol.

Correlation does not imply causation, unfortunately.

There are other metabolic byproducts of the fermentation process which will cause the decrease in pH. While ethanol is one of the byproducts, it is not directly responsible for the change in pH that kills the yeast._________________Anthony